Recommended CS subjects for someone with a mathematics background?

I graduated a couple of years ago with a B.S. in Mathematics and a minor in Computer Science. Since then I've mostly worked in IT/Tech Support. I haven't had much luck finding something to do with my math degree, and don't really have enough programing experience to go directly into a software development job.

I'd like to either go back to school or try to pick up teaching myself where my Computer Science minor left off, but I'm not sure where to go from there. I was wondering if anyone could recommend what fields are in demand and would make the best use of my mathematics background? It seems like machine learning might be a good option, would you agree?